Latch operating means



Dec. 24, 1957 F. JQBUTTER LATCH OPERATING MEANS 2 Sheets-Sheet 1 Filed July 19, 1956 ATTORNEYS Dec, 24, 1957 F. J. BUTTER LATCH OPERATING MEANS Filed July 19,1956

2 Sheets-Sheet 2 FIG. l2.

f/VVENTOR Am J 694 ATTORNEYS 2,817,553 Patented Dec. 24, 1957 ice LATCH OPERATING MEANS Francis J. Butter, Finchfield, Wolverhampton, England, assignor to Josiah Parkes & Sons Limited, Willenhall, England Application July 19, 1956, Serial No. 598,770 Claims priority, application Great Britain August 4, 1955 Claims. (Cl. 292-3363) This invention relates to locks and latches for doors and of the cylindrical type, that is to say of the type in which the spring bolt of a separate tubular latch, fitted in a hole which is bored into the door from and at right angles to its shutting edge and runs radially into another and usually larger hole bored through the thickness of the door, is operable by a spring-loaded retractor which can be actuated by either of two rollbacks associated with knobs on opposite sides of the door, the retractor and the rollbacks on the inner ends of the knob shanks being accommodated in a case, usually cylindrical or nearly so and hereinafter generally referred to as cylindrical, which is fitted in said other or larger hole and usually has axial tubular end extensions affording or fitted with bearings in which rollbacks are mounted for rotation by the knobs.

In locks or latches of this so-called cylindrical type as usually constructed, the r'ollbacks are of segmental form and operate, as followers, upon forwardly presented hearing faces on the retractor for withdrawing it against its spring-loading, .and with it the spring bolt of the latch, when either of the handles or knobs is turned in either direction, said retractor being guided for horizontal movement in fixed guides at either side and having at its forward end vertically opposed claw-like members which take over the extremities of a cross bar or T-shaped rear end of the spring bolt lath or tail. With this usual arrangement, the length or fore-and-aft dimension of the retractor is comparatively small for the length of its travel and the points on its bearing faces with which the extremities of the segmental rollbacks engage are of necessity above and below the horizontal centre plane of the latchbolt, whilst said bearing faces are on opposite sides of the vertical centre plane of said latch bolt. Consequently, the rearward pressure exerted upon the retractor by either of the rollbacks, and irrespective of the direction of rotation of the operating knob, tends to tilt the retractor in its guides and this interferes with smooth running and causes wear.

In a lock or latch of the type referred to and according to the present invention, the retractor instead of being mounted to run in fixed guides, is mounted for free foreand-aft swinging movement in the cylindrical case by pivoted link means. Such link means preferably comprises one or more freely pivoted suspension links, and where there are two or more such links these preferably are arranged as a parallel linkage system so that although the retractor will swing in an arcuate path it will be maintained substantially horizontal during the swinging movement. Where there is only one such link the retractor may be restrained from excessive angular movement about its pivotal connection with said suspension link by a fixed check plate or other fixed abutment whereby the retractor is maintained substantially horizontal during the swinging movement. Obviously any of these arrangements may be inverted so that the link or links operate to support the retractor from below instead of in suspension from above.

In order that the invention may be clearly understood it will now be more fully described with reference to the embodiments shown in the accompanying drawings; wherein:

Fig. 1 is a front elevation of a retractor unit for operating the spring bolt of a separate tubular latch.

Fig. 2 is an end elevation of the unit of Fig. 1.

Fig. 3 is an elevation of the end of the unit opposite to that illustrated in Fig. 2.

Fig. 4 is a front elevation of the unit illustrated in Fig. 1 but with the housing removed.

Fig. 5 is an end elevation of the unit as illustrated in Fig. 4.

Fig. 6 is a rear elevation of the unit as illustrated in Fig. 4.

Fig. 7 is a plan view of the unit as illustrated in Fig. 4.

Fig. 8 is a sectional view partly in elevation of one end of a modified form of the invention.

Fig. 9 is a front elevation, partly in section, of the unit of Fig. 8.

Fig. 10 is a plan view, partly in section, of the unit. of Fig. 8.

Fig. 11 is a sectional view partly in elevation of one end of another modification of the invention.

Fig. 12 is a front elevation partly in section of the unit of Fig. 11; and

Fig. 13 is a plan View, partly in section, of the unit of Fig. 11.

Referring to the drawings and more particularly to Figs. 1 to 7 inclusive, the cylindrical case of the retractor unit comprises two parts, namely the case side or cylindrical cup-shaped part 10 and the cap side or disclike part 11 and both of these parts have axial tubular extensions 12 which afford bearings for the tubular spindle 13 of the two rollbacks 1 3, said spindles 13 extending through said tubular extensions 12 for operative connection to the shanks of the respective knobs (not shown) on opposite sides of the door.

The retractor 15' is in the form of a U-shaped body laid on its side with the free ends of its limbs presented forwardly and terminating in confronting claw or booklike members 16 which take over the extremities of a T-head 1'7 on the tail of the latch bolt (shown in chain lines in Fig. 5), said body being formed on opposite sides of its limbs with upper and lower side wing por tions 18 affording forwardly presented bearing faces for the rollbacks 14.

The retractor 15 is mounted for free: fore-and-aft swinging movement by a parallel link suspension comprising two links 19 having their upper ends mounted on pivots 20 which are fixed to the cap side 11 in horizontally shaped relationship the lower ends of these links being pivotally connected at 21 to correspondingly spaced points on the lower portion of the retractor 15. These links 19, when the retractor 15 is in its normal or forward position as shown, are downwardly and forwardly inclined and they operate in clearance one at each side of the rear portion of the retractor, which rear portion is of correspondingly reduced width, whilst in order not to interfere with the movement of the re ractor 15 said links 19 are rearwardly bowed.

The retractor 15 is loaded toward its normal or forward position by torsion coil spring 22 sleeved upon the pivots 2t) and operating one upon one of said links 19 and the other directly upon the rear face of one of the lower Wings 18 of the retractor 15. Obviously any other appropriate form of arrangement of spring-loading for the retractor may be employed.

The cap side 11 and case side it? are formed with the usual registering or co-extensive forward openings 23, 24 respectively to enable the retractor unit to be passed into position from one side of the door and the claw or hook-like members 16 of the retractor 15 to be engaged with the T-head on the bolt tail of the mortise latch already fitted in its bore in the door.

The length of travel of the retractor 15 in withdrawing the latch bolt is determined by stop plates 25 associated one with each rollback 14 and fixed one to the cap side 11 and the other in the case side of the cylindrical case, said stop plates 25 each afiording limiting abutments for the leading end of the associated rollback 14 according to the direction of rotation imparted thereto by its knob.

Referring now to the embodiment shown in Figs. 3, 9 and 10 in which like reference numbers to those in Figs. 1 to 7 indicate like or analogous parts, the retractor is carried by a single suspension link 1% and is prevented from excessive pivotal movement about its pivotal connection 21 with said link 19 by an abutment in the form of a check plate 26 which has a horizontal under edge and is mounted upon pivot at a position between the suspension link 19 and one of the upper wings 18 of the retractor. The link 19 is centrally disposed to operate in a clearance bifurcation in the rear portion of the retractor 15 and is bowed rearwardly. The spring-loading means for the retractor 15 is not shown, but it may conveniently comprise a torsion coil spring sleeved on the pivot 2t) and operating on the link 19 or directly upon one of the wings 18 of the retractor.

Referring now to the embodiment shown in Figs. ll, 12 and 13 in which the same reference numbers as in Figs. 1 to 7 are used to indicate like or analogous parts, the retractor, instead of being a unitary structure movable bodily by either rollback 14 in either direction of rotation, comprises separate upper and lower independently operable halves 27, 27X respectively each mounted for free fore-and-aft swinging movement by pivotal link means and each adapted by its claw or hook-like member 16 to Withdraw the latch bolt, the upper half retractor 27 being operable by either rollback 14 in one direction of rotation only (clockwise as seen in Fig. 11) and the lower half retractor 27' being operable by either rollback 14 in the opposite direction of rotation only (anticlockwise as seen in Fig. ll). The lower half retractor 27 is mounted by a pair of rearwardly bowed, duplicate suspension links 28, one at each side, which are pivoted upon a common pivot 29 and pivotally connected at 21 to said half retractor 27*, whilst the upper half retractor 27 is mounted by a central pivoted link 30 which supports it from below, said link 30 being pivotally connected at 31 to the said half retractor 27 and pivotally mounted on a fixed pivot 32 in the lower part of the cylindrical case.

In this arrangement, the two half retractors 27, 27 would be independently spring loaded, say by coiled torsion springs (not shown) sleeved on the fixed pivots 29, 32 and operating on either or both of the links 23 and upon the link 39, and in any bolt withdrawal operation the ineffective half retractor 27 or 27 will remain sta tionary, the action being correspondingly easier since the mass to be moved and the spring-loading to be overcome is reduced. In order to prevent excessive pivotal movement of the half retractors 27, 27 about their pivotal connections 31, 2.1 respectively with the links 3! and 23, fixed abutments in the form of check plates 33 of angular section are provided in the forward part of the case side it}, said check plates 33 being set or tilted somewhat to allow clearance for the slight tilting of the half retractors 27, 27 as a result of the angular movement of the links 3%, 28 which control them.

With the retractor suspended or supported by one or more swinging links, the movement imparted to it by the rollbacks is not rectilinear, but the deviation from the straight line movement is not great over the short length of travel necessary to withdraw the latch bolt, and it therefore presents no difficulty providing the retractor is maintained substantially horizontal as by a parallel linkage system or by the use of one or more abutments such as a check plate in conjunction with a single link or duplicate links.

Rearward bowing of the link or links which control the movement of the retractor may be necessary not only so as not to interfere with said movement but also for other purposes. For example, where there is a spindle extending axially through the centre of the case to carry a stop whereby one knob can be put out of action when a push button in the other knob is operated, it may be necessary to bow or offset said link or links rearwardly so as not to interfere with the operation of said spindle.

In a further embodiment (not shown) and having separate spring-loaded and independently operable half retractors which are link controlled, each half retractor may be carried by a parallel linkage system, the lower one from above and the upper one from below, so that they will be maintained substantially horizontal and fixed abutments (such as the check plates 33 in Figs. 11 and 13) are not necessary.

it will be readily appreciated that in any construction according to the invention the retractor, or half retractors, where these are separate and independently operable, may be spring-loaded forwardly by a spring or springs of any appropriate form and operating either directly or indirectly upon the retractor or retractors halves. Also it will be obvious that, insofar as space and design limitations will allow, any essential link of the pivoted link means for the retractor, or either of the half retractors where these are separate and independently operable, may be duplicated to give improved control. Also the pivotal bearings between the links and the fixed pivots on the one hand and the retractor or retractor halves on the other hand would preferably be as long as possible in order to reduce Wear and check lateral swaying in operation.

Having fully described my invention what I claim and desire to secure by Letters Patent is:

1. In a latch assemblage including a housing and a retractor engaging the latch for moving the same between retracted and non-retracted positions, means for supporting said retractor for retracting movement comprising link means having one end pivotally fixed to said housing and the other end pivotally attached to said retractor whereby said retractor is swingably supported in said housing for movement between retracted and non-retracted position.

2. In a latch assemblage including a housing and a retractor engaging the latch for moving the same between retracted and non-retracted positions, means for supporting said retractor for retracting movement comprising a plurality of links each having one end pivotally fixed to said housing and the opposite end pivotally attached to said retractor, the fixed pivots being arranged in parallel relationship with the pivots on said retractor whereby said retractor is swingably supported by said links to move in an arcuate path between retracted and non-retracted positions while remaining at all times substantially horizontal during the swinging movement.

3. In a latch assemblage including a housing and a retractor engaging the latch for moving the same between retracted and non-retracted positions, means for supporting said retractor for retracting movement comprising link means having one end pivotally fixed to said housing and the other end pivotally attached to said retractor whereby said retractor is swingably supported in said housing for movement between retracted and non-retracted positions, and an abutment relatively fixed with respect to said retractor and engageable by said retractor to maintain the latter substantially horizontal during its swinging movement.

4. In a latch assemblage including a housing and two roll-backs movable in opposite directions by handle means, retracting means for moving the latch between retracted and non-retracted positions, said means comprising separate upper and lower retractors each engaging said latch and each being capable alone of retracting said 5 latch, alink pivotally attached at one end to each retractor 5. In the latch assemblage as set forth in claim 4 and having its opposite end pivotally attached to said wherein the lower retractor is suspended by its link from housing whereby each of said retractors is swingably supa fixed pivot above said retractor and wherein the upper ported for movement between retracted and non-retracted reiractol is Supported y its link from fixed P below positions, and an operative connection between each of 5 531d retl'actorsaid retractors and one or the other of said roll-backs whereby movement of one of the latter in one direction References cued m the me of thls Patent actuates one of said retractors to move said latch and UNITED STATES PATENTS movement of the other of said roll-backs in the opposi e 10 1,490,777 La Fortune Apr. 15, 1924 direction actuates the other of said retractors to move 1,903,284 Burton Apr. 4, 1933 said latch. 2,547,256 Cerf Apr. 3, 1951 

